This application claims the priority of German patent document 102 43 318.6, filed Sep. 18, 2002 (PCT International Application No. PCT/EP2003/009606, filed Aug. 29, 2003), the disclosure of which is expressly incorporated by reference herein.
The present invention relates to a driver authorization system and a pushbutton for activating ignition lock functions.
Keyless driver authorization systems (so-called keyless go systems) are now common in vehicles. A keyless go system enables a user of a vehicle to open and start the vehicle without need for a vehicle ignition key. However, the driver must carry a mobile release device (for example, in the form of a credit card) as part of the keyless go system. The keyless go system controls the access authorization and the engine starting authorization for vehicle.
Keyless go systems include a transmitting/receiving device arranged on the motor vehicle for communicating with a mobile release device carried by a user. An authorization interrogation is initiated by an interrogation signal transmitted by the transmitting/receiving device, and is carried out before the vehicle can be opened, or the engine started. If the system detects that a usage-authorized release device is in the vicinity of the motor vehicle, the vehicle is unlocked and the engine start is released.
In conventional driver authorization systems with mechanical ignition key, the access authorization is verified via a mobile release device integrated in the vehicle ignition key, while the driver authorization is verified via the ignition key inserted into the ignition lock.
German patent document DE 197 47 732 A1 discloses a driver authorization system in which an electronically codable on-board identification device is provided which can be released by an external electronic release device (a so-called transponder), which, for example, replaces the mechanical vehicle key. The transponder has a storage element in which the necessary coding for releasing the identification device is stored. For the release device to communicate with the identification device, it must be positioned in the vicinity of the identification device so that a signal radiated by the identification device can be detected and processed by the release device. The signal of the identification device is checked in the release device and answered with a corresponding response signal, the signal variation of which must correspond to the electronic coding of the identification device. If transmitted signal and response signal of the driver authorization system match, at least one vehicle-specific device of the vehicle (for example an electronic controller for driving an internal combustion engine of the vehicle) is released.
It is also known to integrate the release device into an ignition key. The disadvantage of this arrangement is that, apart from the electronic communication between the identification device and the release device, both the ignition key and the ignition lock must have matching shape features. Due to the multiplicity of different locking systems in ignition keys, this complicates considerably the integration of an electronic driver authorization system.
To solve this problem, German patent document DE 197 47 732 A1 discloses an identification device which comprises a receptacle into which a release device can be inserted, and which exhibits an actuating device which can be triggered by the release device. It is no longer necessary to use an additional ignition key.
From German patent document DE 198 53 075 A1, it is also known that the release device can be brought into two positions, one being used to detect the release device and the other being used to trigger an ignition lock function.
In German patent document DE 198 60 350 A1, after a successful release dialog between an on-board identification device and a mobile identification transmitter, an engine start authorization control unit releases an actuating device. The latter is implemented with minimum installation space by providing a manually operable actuator with a securing module which correspondingly releases the actuator via the identification device. The released actuator enables the steering wheel to be mechanically unlocked and the engine to be started. The actuator can be constructed as a rotary switch which is associated with a pushbutton, which is used for starting the release dialog. To start the entire process including the required authorization interrogation, an electrical pushbutton is integrated, for example into the gearstick or gear selection lever at the top.
Known keyless engine start authorization control systems are mostly incorporated in keyless access authorization control systems, since the same hardware components can be used for performing the desired question/answer dialog.
Even if such a driver authorization unit as described above increases the operating convenience compared with conventional key systems, an additional actuating device must be provided in the passenger compartment near the driver, for initiating the start process. This actuating device impedes the vehicle design of the cockpit since additional space must be provided for it. Moreover, there are additional costs for switches and their cabling.
Due to the high susceptibility of the keyless go systems to radio interference sources such as, for example, garage door openers, radio headphones, etc., vehicles with keyless go systems also require an emergency engine start authorization system, consisting of ignition lock and key. Such radio interference sources have been released by the communication authority for frequency bands which are also used by keyless go systems. There is, therefore, the problem of always having to equip vehicles with keyless go systems with the standard electronic ignition lock and ignition key which are also provided for non-keyless go systems. In addition, vehicles with keyless go systems are equipped with an additional pushbutton connected to the electronic ignition lock, which increases production costs because the driver authorization system cannot be produced uniformly for vehicles with/without keyless go systems.
It is therefore an object of the present invention to provide a keyless go driver authorization system in which various ignition lock functions can be activated reliably and simply, without installing an operating element specially provided for this purpose in a vehicle.
This and other objects and advantages are achieved by the authorization system according to the invention, in which the ignition lock functions can be activated by means of the control unit, using a pushbutton that can be mounted and actuated on, and removed from, the ignition lock itself, without requiring the ignition lock to be operated in the form of rotating a key inserted into a rotary ignition lock.
The driver authorization system according to the invention has the advantage that it can be produced in the same manner for motor vehicles, both with and without keyless go systems. That is, the electronic ignition lock control unit (the electronic ignition lock with the associated control unit) can be produced identically for systems with or without keyless go. No additional cabling to a pushbutton is necessary for motor vehicles with a keyless go system. The electronic ignition lock does not have to be adapted to the keyless go system.
A further advantage of the invention is that the driver does not need to remember a new position for the starting button for starting the motor vehicle in a keyless go mode. Instead, the motor vehicle can be started from the same position independently of whether the motor vehicle is operated with ignition key or in keyless go mode.
It is also advantageous that the keyless go mode can be replaced by the standard system simply by removing the pushbutton. This is of particular importance in vehicles which are equipped with keyless go system. Although the pushbutton generally remains inserted in such vehicles, if the keyless go system fails for the above-mentioned reasons, the pushbutton can be immediately removed, and the driver can start the vehicle.
Integrating the mobile release device into the ignition key has the advantage that the driver does not need to carry the ignition key in addition to the mobile unit.
A further substantial cost saving is that no additional space needs to be provided for a starting button in the design of the cockpit.
The concentration on the system responsible for the driver authorization results in an optimization of installation space: Additional switches, cabling are avoided, and the space required for the driver authorization system in the passenger compartment is reduced.
The operator-friendly positioning of the pushbutton on the top of the gear selection lever or of the gearstick is no longer possible in “shift by wire” vehicles. Since the operating elements are positioned close to the steering wheel, the pushbutton is not positioned at the top in order to avoid operating errors by the driver. An operating-friendly pushbutton position is thus no longer available.
In one embodiment of the invention, the pushbutton can be mounted and actuated on and removed from the vehicle ignition lock and, when it is operated, the actuating element interacts with a release switch in the on-board ignition lock in order to activate ignition lock functions without rotating the rotary switch.
The pushbutton according to the invention has the advantage that it can be produced with little expenditure, and independently of the ignition lock unit.
The contactless power supply to the pushbutton via inductive voltage coupling is more maintenance-free than a direct mechanical coupling since the tractive forces are lower in the inductive coupling.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.